<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>百分比布局</title>
</head>
<body>
    <div class="main"></div>
</body>
<style>
    body{
        margin: 0;
    }
    .main{
        width:93.6%;
        margin: 0 auto;
        height: 40px;
        background-color: antiquewhite;
        border-radius: 15px;
    }
</style>
</html>